We have previously described that the quorum-sensing autoinducer, N-butyryl-L-homoserine lactone (C4-HSL) enhances mexAB-oprM expression, and this C4-HSL-mediated enhancement of mexAB-oprM expression was repressed by MexT, a positive regulator of the mexEF-oprN operon. In this study, we investigated the interaction between C4-HSL and mexR by using a knockout mutant. It was indicated that the C4-HSL-mediated enhancement of mexAB-oprM expression occurred without MexR-mediated regulation. Furthermore, it was observed that the C4-HSL-mediated enhancement of mexAB-oprM expression without the MexR-mediated regulation was repressed by MexT.
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http://dx.doi.org/10.1111/j.1348-0421.2004.tb03533.x | DOI Listing |
Front Microbiol
January 2025
Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland.
Antibiotic-resistant Gram-negative bacteria are an increasing threat to human health. Strategies to restore antibiotic efficacy include targeting multidrug efflux pumps by competitive efflux pump inhibitors. These could be derived from natural substrates of these efflux systems.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
() infections are increasingly challenging due to their propensity to form biofilms and low outer membrane permeability, especially in chronically infected patients with thick mucus. exhibits multiple drug resistance mechanisms, making it one of the most significant global public health threats. In this study, we found that moxifloxacin (MXC) and antibacterial peptides (ε-poly-l-lysine, ε-PLL) exhibited a synergistic effect against multidrug-resistant (MDR-).
View Article and Find Full Text PDFMicrobiol Spectr
January 2025
UMR CNRS 6249 Chrono-Environnement, UFR Santé, Université Bourgogne Franche-Comté, Besançon, France.
Exposure of to cinnamaldehyde (CNA), a natural electrophilic antimicrobial often used as self-medication to treat mild infections, triggers overproduction of the MexAB-OprM efflux system, leading to multidrug resistance. In this study, we demonstrate that CNA exposure induces expression of genes regulated by the two-component system AmgRS. AmgRS activates MexAB-OprM production, independent of repressors MexR and NalD.
View Article and Find Full Text PDFJ Glob Antimicrob Resist
December 2024
Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Infectious Diseases, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Research Center for Antibiotic Stewardship and Antimicrobial Resistance, Tehran University of Medical Sciences, Tehran, Iran. Electronic address:
Objectives: Pseudomonas aeruginosa is a major opportunistic pathogen responsible for a wide range of infections. The emergence of antibiotic resistance in this pathogen poses a significant public health challenge. This study aims to conduct a comprehensive meta-analysis of studies conducted in Iran to determine the frequency of key antibiotic resistance mechanisms in Pseudomonas aeruginosa and their association with multidrug-resistant and extensively drug-resistant strains or pandrug-resistant strains.
View Article and Find Full Text PDFAntimicrob Agents Chemother
October 2024
IHMA, Schaumburg, Illinois, USA.
Ceftazidime-avibactam (CZA) and ceftolozane-tazobactam (C/T) are important agents for treating multidrug-resistant infections. In this study, we evaluated the molecular characteristics of 300 globally collected clinical isolates non-susceptible (NS) to CZA, C/T, or both agents. Isolates were CZA-NS and C/T-NS ( = 57), CZA-susceptible (S) and C/T-NS ( = 145), or CZA-NS and C/T-S ( = 98) selected from the Antimicrobial Testing Leadership and Surveillance (ATLAS) surveillance program from 2020 to 2021.
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